CARE+CLEAR

Improving image quality and optimizing dose in every Artis system.

In addition to protecting patients from excessive radiation exposure, physicians, technicians and other medical staff should be protected from unnecessary (i.e. scattered) radiation as well.Care about your own safety and want to find out how you can reduce radiation exposure in addition to our CARE+CLEAR package? Here you can discover different ways of reducing radiation dose in the interventional lab.

Protect the operator

Reduce dose for the operator

Scattered radiation does not come directly from the X-ray tube, but rather is scattered by the patient, table, or other devices within the path of the X-ray beam. Usually most of the scattered radiation is generated where the X-ray beam hits the patient.

Collimation should be used if possbile.

1. Collimate if applicable

Scattered radiation is approximately proportional to dose area product, that means 50% area translates into 50% scattered radiation (if dose = constant)! The collimation also results in an improved image quality (less scattered radiation, better contrast).

2. Stay away from the tube side

Scattered radiation can be reduced by installing the lateral C-arm with the tube on the left side of the table when the medical staff works on the right. Scattered radiation is mainly generated at the beam entrance location of the patient, which is on the left side in this configuration. At the operator’s working position (right side), radiation exposure from scatter is much lower.

Scattered radiation decreases with distance from the source (i.e. the beam entrance location of the patient).

3. Stay away from the patient

Scattered radiation is roughly proportional to the dose area product (DAP) and decreases with distance squared to the location the scatter is generated. That is, twice the distance results in a quarter of the scattered radiation.

Lower and upper radiation protection.

4. Shield as much as possible

Scattered radiation is attenuated by matter. Typical shields:

Apron (lead)

Glass shields (lead)

Glasses (lead)

Lower/upper body protection

Body (tissue, bone)

5. Bring the monitor as close as possible

The optimal eye to monitor distance is 1 meter or less for non-zoomed display.

6. RaySafe i3 Builds a Better Radiation Safety Culture™

• The Real-Time Display enables immediate changes in working procedures in order to minimize dose• The Personal Dosimeters supply the Real-Time Display with information about each individual’s personal dose• The Dose View software makes it easy to review radiation data• The optional Dose Manager software makes it easy to report, export and archive radiation data

The RaySafe i3 dosimeter measures and records radiation every second and transfers the data wirelessly to the real time display. It is maintenance free, easy to wear and can be personalized with different colors and names.

i2 DosimeterAn active dosimeter that measures and records radiation every second. Data is transferred wirelessly to the i2 real-time display. It is maintenance-free, easy to wear and can be personalized with different colors and names.

Reduce dose for the patient

Pedals for generating standard acquisition and low-dose acquisition.

1. Select the adequate protocol

For especially dose-sensitive patients, it is possible to generate a special low-dose acquisition protocol. An acquisition pedal of the footswitch can be configured as a low-dose acquisition alternative to the ECC/TSC. A dose saving of 67% can be achieved by using an acquisition dose of 80 nGy/f instead of 240 nGy/f for interventional cardiology and an acquisition dose of 0.8 μGy/f instead of 2.4 μGy/f for interventional radiology.

Choose a proper organ program

Use low dose acquisition

Use Fluoro Loop (Store Fluoro)

Use Low Dose 3D protocols

2. Minimize footswitch-on time

Footswitch-on time: footswitch-on time controls how long the beam is on the body and thus how long the body is irradiated; less time means less radiation.

Less footswitch-on time ⇒ less skin doseExample: ½ time on the pedal ⇒ ½ skin dose, ½ dose area product

Reduction in patient dose by lowering the pulse rate during fluoroscopy.

3. Use low frame rate

High frame rates are used to visualize fast motion without stroboscopic effects. However, the higher the frame rate, the more radiation. Therefore it is best to keep the frame rate as low as possible.

C-arm, two different SIDs, constant table height, location of the IRP.

5. Lower SID as much as applicable

SID: according to the quadratic law and a constant requested dose at the detector, a greater distance between the source and the imager increases the patient entrance dose. Raising SID from 105 cm (= SID 1) to 120 cm (= SID 2) increases patient entrance dose (i.e. the dose at the IRP) by approximately 30%.

The anti-scattering grid can be removed by simply pressing a button on the flat detector housing.

6. Remove grid and increase SID

“Air Gap Technique” (for small patients only, <20 kg)A simple way to reduce the dose in pediatric examinations, especially for babies or very thin patients, when scatter radiation can be expected to be negligible, is to remove the scatter grid in the flat detector housing.The grid factor (i.e. the absorption of primary radiation due to the anti-scatter grid compared to free air) is 1.35, which translates into a dose saving of 26%* when removing the grid.

7. Use shallow angles as much as possible

An increase in patient’s thickness of about 3 cm results in twice the entrance dose for a constant detector entrance dose. This rule of thumb is based on the assumption that tissue absorbs radiation in a similar manner as water and that a certain quality of beam is applied.

Simplified model showing the effect on patient entrance dose when the projection is angulated.

A similar effect occurs when the direction of projection is changed to an oblique position. Because the shape of the body is more oval than circular, the length of the X-ray beam is now longer, resulting in a higher entrance dose. True values may differ significantly since the body is not really a homogeneous ellipsoid but consists of bones, organs, etc.